Search
Close this search box.
Notifications
Clear all

Viscoelastic Material Model in ABAQUS Using Experimental Creep Data

5 Posts
3 Users
0 Reactions
621 Views
Posts: 2
Topic starter
(@througheye)
New Member
Joined: 16 years ago

Hi

Ive obtained a creep curve for some PVC (creep strain versus time) by experimental measurement at room temperature and under a constant stress of 20 MPa. Id like to use this data to calibrate a time-dependent viscoelastic material model in ABAQUS. Im following what I believe is the correct procedure in converting my creep strain data in to the normalised shear relaxation modulus (gR(t)).

However, when I put these data into ABAQUS, I get an error message because some of my normalised values are greater than 1 (which I accept is odd). I presume I must be doing something wrong with my calculations. My spreadsheet can be picked up from here:

[url] http://dl.dropbox.com/u/3897156/PVC%20Creep%20Data%20and%20ABQ%20Viscoelastic%20Data.xlsx [/url]

If anyone has the time and/or inclination to have a look Id be very grateful. Any other suggestions concerning the error message would be highly appreciated.

Many thanks

James

4 Replies
Posts: 2
Topic starter
(@througheye)
New Member
Joined: 16 years ago

All sorted now. I just had to add the instantaneous elastic strain to my measured creep data (which Id previously removed) and everything dropped out nicely!

James

4 Replies
Posts: 3998
(@jorgen)
Member
Joined: 5 years ago

It is good to hear you figured it out.

-Jorgen

Reply
Posts: 3
(@rsh1649)
New Member
Joined: 9 years ago

[QUOTE=Jorgen,10487]It is good to hear you figured it out.

-Jorgen

Hi Jorgen

I have a problem: Ive obtained a creep curve of elastomer (strain-time), i calculate E(t)=Stress/epsilont(t)

Then i calculate G(t)=E(t)/2(1+ni) and gR=G(t)/G0

It is correct to define viscoelastic behavior of elastomer?

What is LONG TERM normalized shear compliance? how I obtained its? abaqus asks me LONG TERM normalized shear compliance when i use creep shear data

Reply
Posts: 3998
(@jorgen)
Member
Joined: 5 years ago

The long-term normalized shear compliance is exactly what is sounds like: the normalized shear stress at very long times. You can get this value from experimental tests.

-Jorgen

Reply
Share: